Objective: To determine whether maternal plasma concentrations of placental growth factor (PlGF), soluble endoglin (sEng), and soluble vascular endothelial growth factor receptor-1 (sVEGFR-1) at 30-34 weeks of gestation can identify patients at risk for stillbirth, late preeclampsia, and delivery of small-for-gestational-age (SGA) neonates.
Study design: A prospective cohort study included 1269 singleton pregnant women from whom blood samples were obtained at 30-34 weeks of gestation and who delivered at >34 weeks of gestation. Plasma concentrations of PlGF, sEng, and sVEGFR-1 were determined by enzyme-linked immunosorbent assay.
Results: The prevalence of late (>34 weeks of gestation) preeclampsia, severe late preeclampsia, stillbirth, and SGA was 3.2% (n = 40), 1.8% (n = 23), 0.4% (n = 5), and 8.5% (n = 108), respectively. A plasma concentration of PlGF/sEng <0.3 MoM was associated with severe late preeclampsia (adjusted odds ratio, 16); the addition of PlGF/sEng to clinical risk factors increased the area under the receiver-operating characteristic curve from 0.76 to 0.88 (P = .03). The ratio of PlGF/sEng or PlGF/sVEGFR-1 in the third trimester outperformed those obtained in the first or second trimester and uterine artery Doppler velocimetry at 20-25 weeks of gestation for the prediction of severe late preeclampsia (comparison of areas under the receiver-operating characteristic curve; each P ≤ .02). Both PlGF/sEng and PlGF/sVEGFR-1 ratios achieved a sensitivity of 74% with a fixed false-positive rate of 15% for the identification of severe late preeclampsia. A plasma concentration of PlGF/sVEGFR-1 <0.12 MoM at 30-34 weeks of gestation had a sensitivity of 80%, a specificity of 94%, and a likelihood ratio of a positive test of 14 for the identification of subsequent stillbirth. Similar findings (sensitivity 80%; specificity 93%) were observed in a separate case-control study.
Conclusion: Risk assessment for stillbirth and severe late preeclampsia in the third trimester is possible with the determination of maternal plasma concentrations of angiogenic and antiangiogenic factors at 30-34 weeks of gestation.
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